Automatic load control



y 25, 1939- E. M CABE 7 155 I AUTOMATIC LOAD CONTROL Filed Aug. 5, 1.936 3 Sheets-Sheet 1 F IG. 1 IQK' SRXBE f f I ATTORNEY July 25, 1939. l. E. M CABE AUTOMATIC LOAD CONTROL Filed Aug. 5, 1956 3 Sheets-Sheet 2 v INVENTOR IRA E- M CABE XS ATTORNEY July 25, 1939.

I. E." M CABE AUTOMATIC LOAD CONTROL Filed Aug. 5, 1936 3 Sheets-Sheet 5 INVENTOR IRA E. M CABE BY 6 M M ATTORNEY Patented July 25, 1939- su'romnc LOAD common In E. McCabe Chicago, Ill. Application August 5, 1936, Serial No. 94,333 '3 Claims. 01. 219-38) This invention relates to an automatic control device and more particularly to a device of this character for automatically limiting the load uD a commercial .electric service line for domestic purposes, such as used for operating electric ranges and water heaters in dwellings or buildings.

a At the present time commercial program clockshave been installed in commercial circuitsfor l0 cutting out a'n'electric water heater during the peak hours of service without interfering with the operation of a domestic electric range connected with the commercial line, so that the user may have only periods of water heating during the power company's ofl peak" load periods.

The use of such devices have made it possible for the power companies to grant special rates to customers employing them. However, the period for water heating as provided by the power company may be such that at certaintimes, as on wash-daywthe hot water requirements would be .diiiicult to maintain due to either short periods of heating or long periods of no heating. A

'25 It is an object of this invention to provide a device which will operate during the "0!! peak" period. when both electric range and electric 'water heater may be normally employed which will automatically cu out the water heater during any period when he load of the range reaches a predetermined degree. Thus in addition to insuring suflicient hot water at all times 'theability to obtain long periods for, water heating would make possible the use of smaller tanks and consequently reduce the plant cost for the customer,

For instance,. the program switch might be set to throw the current of! to the electric water heater only'during' the hours of the system peak, a

- as for example, from 4 P. M. to 6 P. M. At all other times, there would be no question of establishing distribution transiormer peaks or -ove'r-' loading secondaries if the :water'heater were cut out whenever the range load exceeded a predetermined degree, as 1000 watts. The special "oi! peak" rate ,by the power company would be Justified by the assurance that the-water heater required no increase iii plant investment. Load limiters are at present available for performing the duties a stated but they do not incorporate .the peak period cut out feature necessitating the employment of separate devices when such a coml ination is desired.

With this and other objects in view, reference II is made to the accompanying sheets of drawings which illustrate a preferred form of this invention. 7

. Figure 1 is a view in front elevation of a preferred form of this invention illustrating the position assumed by the control parts just following s the termination of the peak hours with theelectric water heater circuit mercury tube switch.

Figure 2 is a fragmentary detail view illustratclosed through the ing the position assumed by the parts during the -'10 "oif peak" period when the combined load of the electric range and electric water heater exceed a predetermined amount and the circuit to the water heater is broken through the mercury switch. L T

Figure 3 is a view similar to Figure 2, showing the position assumed by the parts when'the circuit to the electric water heater is broken through the mercury switch during the peak period.

Figure 4 is a diagrammatical view illustrating 20 this improved device, an electric range, an electric water heater, and a wiring diagram connecting the same to the commercial circuit.

Figure 1 illustrates a program clock B of commercial construction including a rotating annular 28 dial D having adjustable stops C and C einbracing the periphery of the dial D for determining the time during which the mercury tube switch T is opened or closed. The mercury tube switch T is carried upon a snap action mechanism M so constructed in accordance with this applicant's prior Patent No.,1,734, 016 of October 29, 1929, in which the actuating member Ais provided with 9. 'lug L adapted to be engaged successively ,by the stops C and C; whereby the stop C throws to the switch'to the open position and the stop C throws the switch to the closed position.

The parts above described are all of commercial. construction and are in commercial use at the present time. I

In carrying out this invention, a solenoid S is employed and the snap action mechanism M is. modified to the extent thatthe inercury tube switch carrying bar with the angular or sloping surfaces ofthe patent is divided, as shown in Fig- 45 ures 1: to 3, inclusive, to include a pivoted member .I provided with the sloping surfaces 2 and 3 with ly arranged and pivoted member 6 by'a linlrv I pivoted at one end to'the member l and at the other end to the member] by a lost motion connection including a pin I upon the member i and a slot 9 in said link, whereby said linkmay slide over the pin 8. The core Id of the solenoid 8 is connected by means of the jointed arms II and I! to the, mercury tube switch carrier I3,

. mounted'upon the membert. The arm I! is rigidly connected to said carrier or member and the arm II is pivotally connected to the upper :end of the core in. when the solenoid is not energized sufliciently to actuate its core, the core will assume the position shown-in Figure -'1.

In Figure 1; the snap action M has been actu- Q) ated by the clock-to rotate the member I to the limit of its movement in the direction to close the mercury tube switch T and the weight of the core,

5 l0 rotates-the member 6 to the limit of its movement to close the mercury tube switch T, so that the right hand 'end of the slot 9 in the link 'I is in engagement with the pin 8. a Should the solenoid be suiliciently energized to lift its coreflfl, it will impart through arms H r and I2 a rotation in the opposite direction to the member 6 to openthe mercury tube switch without interfering with the normal position of the member I through the lost motion connection in the-link]. a a

It is immaterial whether or not the solenoidcore be in itsuppermost position when the peak load is reached and theprogram clockactuates thesnap mechanism to throw the mercury. tube .130 switch into the open position, as shown in Figure 3. when the member I isrotated to the limit of its movement in the opposite direction by the snap action from that illustrated in Figure 1, such movement is transmitted'by the pin 8 1 in engaging the right hand end of the 9 which in turn rotates the member 6 to the limit of its movement and in so doing throws the mercury tube switch to the open position as shown in Figure 3.

4 Figure 4 illustratesthe program clock-B adapted to operate the mercury tube switch T through the snap movement M, the housing for said mechanism also supporting the solenoid S.' The electric range is diagrammatically illustrated as 5 including the surface heaters-Rand R and the oven heater 0 and the oven temperature control 0'. The electricwater heater H as well as the range are of the usual commercial, structure.

The wiring illustrates 'acommercial three-line system X, Y and Z, so that when the lines X and Z are connected througlrany of the instruments, a'115 volt circuit is completed, likewise when the lines Y and' Z are connected I through any of the instruments, a 230 volt c cuit is completed.

The line X is-connect'edto binding post M from which the current passes through the electric clock motor, notshown, to binding post l5 which,

in turn is connected to line Z. The current from co binding post I. also passes through the mercury tube switch-T to the binding post and from thence through the electric water heater H to the binding post I! connected to the 'line Z. The

current from binding post ll also passes through solenoid S, binding post I! through the electric range to binding post II which is connected to line 2.. The oven heater and oven temperature 'control are connectedin series .i n this circuit a connection between the solenoid core and the operation of the program clock closing the V mercury tube switch T. At medium or low range heat the combined load of the electric range and electric water heater is genera1ly.below the maximum load allowed during ofi peak periods, but there are periods particularly .during cooking operations that high heat is desired for the shortperiods which would increase the load to exceed the amount desirable for the off peak period. The

- commercial line during the offpeak period remains within the limits desired. As the maximum loads do not eilectively energize the sole- 20 noid but for short periods at a time, the cutting out of the electric water heater for these short periods'does not act as an inconvenience to the householder.

What I claim is: Y

1, In a system of electrical distribution'for a plurality of electrical devices including an elec-. trically heated water heater and a source of electricalenergy supply, a control for limitingthe operation of the electric, heater to periods when the operation of any or all of the other devices does not exceeda maximum wattage including clock actuated means to: render said control'in operative during predetermined hours to cutout the electric heater.

2. In a system of electrical distribution for a plurality of electrical devices including an electrically heated water heater connected in circuit to a sourccof electricity, a switch interposed in the circut from said water heater to said source, a mechanically operated switching mechanism therefor including a pivoted member or limited pivotal movement actuated by said mechanism, an'additional pivoted member of limited pivotal movement carrying said switch, a link pivoted at its respective ends to said respective pivoted members having a lost motion connection with one 'of said members, whereby-rotation of the first member to the limit of its travel in one direction opens said switch and in the opposite direction closes said-switch, and a solenoid in circuit with the other said devices adapted to be effectively energized-to move its coreupon the load of the otherde'vices reaching a predetermined wattage,

switch carrying memberadapted upon eflectLe energizaition 0f the solenoid to rotate said switch "been closed by'said mechanism.

'3. Ina system of electrical distribution for a plurality of electricalrdevices including anele'c-' -trically heatedwater heater connected in circuit to a source of electricity,'a switch interposed in the circuit from said water heater and said source, a mechanically operated switching mechanism therefor including apivotal member of limited pivotal movement actuated by said mechanism, an additional pivoted member of pivotal movement carrying said switch, a. link pivoted at its respective ends to said respective pivoted members having a lost motion connectio f with one of said members, whereby rotation of the first member to the. limit of its travel in one direction openssaid switch and in the opposite direction closes said switch, and a solenoid in 7 circuit with the other said devices adapted to be effectively energized to lift its core upon the load of the other devices reaching a predetermined wattage, a connectlof between the solenoid core 5 and switch carrying member adapted upon eflecswitch carrying member to open said swltch after 1t had been closed by said mechanism, a program clock and means carried thereby to operate the switching mechanism at predetermined periods IRA E. MOC ABE. 

